[GEM-dev] Playing HDV video with frame accurate seeking on Linux

B. Bogart ben at ekran.org
Wed Aug 26 04:59:14 CEST 2009


Hey Chris,

I scaled my video down to 1024x768 (from 1440x1080) and not seeing any
improvement. Using mjpeg or any other codec I recall using before gives
me the same results as my mpg2 with all iframes.

I'll keep messing with settings to increase disk IO and decrease decoding.

I wonder has anyone played HDV footage using frame seeking on Linux?

I'm seeing all kinds of things, like ffmpeg-mt for multi core systems,
for mplayer, but nothing that will help in PD.

Say Johannes, does gstreamer allow you to play video backwards? In
mplayer the xv output uses much less cpu than gl or gl2, so opening a xv
port to play the video, rather than GL, could be the trick?

I managed to encode a lossless jpeg AVI from ffmpeg, but that does not
load in Gem, so I could not test it.

I'll keep tinkering.

.b.



chris clepper wrote:
> On Tue, Aug 25, 2009 at 5:02 PM, B. Bogart <ben at ekran.org
> <mailto:ben at ekran.org>> wrote:
> 
>     One thing that is clear is that the CPU overhead is too high, but the
>     disk usage very very low. I'd rather balance things out to use more disk
>     IO to save decoding cycles.
> 
> 
> That is the key to all codecs.  Uncompressed doesn't require CPU to
> decode but the disk requirements can be very high.  Delivery codecs like
> MPEG and H.264 are the reverse situation.
> 
> Use a JPEG based or professional capture codec like DVC whenever possible. 




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